For controlling engines, typically internal combustion engines, sensors exist which indicate a position or location of a moving component, for example the crankshaft, of the engine. In such engines it is customary to use a sensor wheel, fixedly mounted on the crankshaft, to generate signals at certain angles by a sensor whenever a marking begins or ends on the sensor wheel.
German Publication No. DE 100 63 755 A1 describes a method for ascertaining and verifying the occurrence of a singularity for a rectangular-pulse signal. The singularity is recognized if the sum of the time periods between predefinable signal intervals directly before and after the singularity is smaller than the period of time in which the singularity occurs. This method is used, for example, for evaluating a rotation of a rotating body, having a reference mark, which is connected to the crankshaft or the camshaft of an internal combustion engine. The method is carried out in the control unit of the internal combustion engine.
To be able to carry out a synchronization with the instantaneous engine position, one or multiple markings is/are usually left out in the sensor wheel, as also described in German Publication No. DE 100 63 755 A1. However, since the marking positions only very roughly represent the instantaneous engine position, an angular basis is produced via which intermediate positions may be determined with the aid of a precisely defined number of pulses between two sensor signals. For this purpose it is necessary, among other things, to predict the period of time until the next sensor signal.
A method for determining a differential angle of an internal combustion engine between a first angle event and a second angle event is described in Application No. DE 10 2005 047 922 A1. The first angle event has a defined time interval with respect to the second angle event. In carrying out the method, the tooth times of the preceding teeth are ascertained, beginning with the crankshaft angle of the second angle event, and successively added to the time interval between the first angle event and the second angle event, the tooth angles of the teeth included in the particular tooth times being added to the differential angle, and the tooth times being ascertained from the tooth times of a preceding power stroke multiplied by a correction factor.
It is customary to derive the prediction of the instantaneous time interval from the preceding time interval. In addition, the so-called increment angle prediction (IAP) method for stepwise prediction of an angle, which also describes the relationships of the sensor signals with regard to a 720° rotation of the crankshaft, results in an improvement. Furthermore, for computing injection times it may also be necessary to take multiple future time intervals into account. The so-called multi-increment angle prediction (MIAP) algorithm is used for this purpose. Here as well, the future increments are computed based on the corresponding measured increments in the past, as described in Application No. DE 10 2005 047 922 A1.